An acrylonitrile-butadiene-styrene (hereinafter referred to as ABS) resin is applied to various products, such as automobile appliances, electric and electronic products, and office equipment, due to stiffness and chemical resistance of acrylonitrile therein and processability, mechanical strength and beautiful appearance of butadiene and styrene therein.
Such an ABS resin is generally subjected to post-processing. As a representative post-processing step, there is a painting process. In this painting process, a chemical solvent, such as a thinner, is used to properly coat a paint on an ABS resin. However, when such a chemical solvent is used, the chemical solvent chemically attacks the ABS resin, whereby problems, such as crack generation in the ABS resin, may occur. In addition, such minute cracks eventually cause defects, such as pinholes and stains, in the paint.
Accordingly, methods, such as rubber content increase, rubber size increase, acrylonitrile content increase, and resin molecular weight increase, have been mainly used to reinforce chemical resistance against a chemical solvent. However, these methods eventually lower fluidity of an ABS resin, whereby residual stress of a molded article prior to painting increases. Accordingly, problems, such as pinhole generation in paint, are still present. Therefore, there is an urgent need for chemical resistance increase and paintability improvement of an ABS resin.